1. Field of the Invention
The invention relates to building construction components and, more particularly, to building construction components fabricated from metal such as headers, sills, trusses, girders and support posts.
2. Description of the Invention Background
Traditionally, the material of choice for new residential and commercial building framing construction has been wood. However, over the years, the rising costs of lumber and labor required to install wood framing components have placed the dream of owning a newly constructed home out of the economic reach of many families. Likewise, such increasing costs have contributed to the slowing of the development and advancement of urban renewal plans in many cities. Other problems such as the susceptibility to fire and insect damage, rotting, etc. are commonly associated with wood building products.
In view of the foregoing problems and shortcomings of wood construction, steel is rapidly gaining acceptance among homebuilders and homeowners alike due to its cost effectiveness, dimensional stability, noncombustibility, insect resistance, durability, high strength-to-weight ratio and recycleability. These advantages have long been recognized by the commercial construction industry wherein steel has been the material of choice for several decades.
Regardless of whether a building comprises a multistory commercial structure or a single story residence, C-shaped metal studs and tracks are commonly used in their construction. FIG. 1 illustrates a conventional C-shaped metal stud 10 that has a web 12 and a pair of flanges 14. A lip 16 is also formed on the end of each flange 14 to further strengthen the stud. Such studs 10 are commonly fabricated from cold-formed steel utilizing conventional rollforming techniques. Similarly, the conventional tracks 20 that are employed by the building trades each have a web 22 and a pair of flanges 24. The tracks 20 are similar in construction as the C-shaped studs, but lack the lack the lips that are commonly formed on the ends of the stud flanges. See FIG. 2.
In most construction applications, walls are constructed by attaching a series of C-shaped studs between a top track and a bottom track. The bottom track is usually attached to the floor structure by screws or other fasteners and the top track is usually attached to the ceiling joists. The ends of the studs are inserted into the top and bottom tracks and are attached thereto by screws, welds, etc. After the wall frame is constructed, then the desired wallboard material is attached to the flanges of the studs and tracks utilizing screws or other fasteners to complete the wall assembly.
In those walls that require door and/or window openings to be framed therein, a header is constructed to transfer loads occurring above the opening to the vertically extending studs adjacent the opening. The studs that define the vertical boundaries of the opening are often referred to as the “jamb” studs. FIGS. 3-5 illustrate one prior header and jamb stud arrangement that is formed utilizing conventional C-shaped studs and tracks. As can be seen in FIGS. 3 and 4, the header 30 is formed by attaching a first C-shaped stud 32 to a track 40 such that the flanges 36 of the stud 32 are received between the flanges 42 of the track 40. A second upwardly facing piece of track 46 is then attached to the web 34 of the first stud 32. Such header 30 is commonly fabricated by attaching these components together with fasteners such as screws 49 or the like. The use of such screws, however, creates undesirable buildups which can lead to drywall finishing problems. In the alternative, the components may be welded together which adds to assembly time and expense.
Likewise, the jamb studs 50 are each commonly formed by attaching a C-shaped stud 52 to another piece of track 60 such that the flanges 56 of the stud 52 are received between the flanges 64 of the track 60 and then attaching the web 72 of another stud 70 to the web 64 of the track 60. These components are also commonly coupled together with screws 49 which can lead to drywall finishing problems. In the alternative, they may be welded together to form the jamb stud 50. Such assembly approach requires additional skilled labor. These combinations of components have been found to provide the jamb stud with a sufficient amount of strength to receive the loads from the header without failing or buckling.
To complete the header assembly, the header 30 is then attached to each jamb stud 50 by corresponding L-shaped clips 80. The clips 80 are welded or screwed to each jamb stud 50. In addition, sections of studs 82 are attached between the track 60 and the section of upper track (not shown) to which the upper ends of the jamb studs 50 are attached. Such stud segments 82 are often referred to in the industry as “cripple studs” and further transfer loads from the upper structures to the header.
FIG. 6 illustrates a prior truss chord 90 that is fabricated utilizing conventional C-shaped studs. By way of background, trusses are used to form the support frame for a roof or, in some applications, are used to form the support for an upper floor. The upper and lower portions of the truss are known as the “chords” and the members that extend between the chords are called “webs”. As can be seen in FIG. 6, a typical method employed to form a truss chord 90 is to weld two C-shaped studs 92 together as shown. The truss webs are formed from other pieces of C-shaped studs 94 that are fastened to the chord 90 by screws, bolts etc. This arrangement, however, is labor intensive because studs have to be welded together to form the necessary chords.
Conventional C-shaped studs and tracks are also used to form support posts for supporting loads from the structures located above the posts. FIG. 7 illustrates a prior method of constructing a support post. As can be seen in that Figure, a total of 3 C-shaped studs 102 and two tracks 104 are employed. The studs 102 and tracks 104 may be connected together by a collection of screws or by welding. Both fastening methods, however, are time consuming and attribute to higher labor costs associated with their fabrication.
Floors are also constructed utilizing components that are somewhat identical to C-shaped studs and tracks utilized to form the wall frames for the structure. However, the tracks and C-shaped members used to form the floor structure can be larger than those like-shaped components used to form wall structures. The floor of a structure is commonly formed from a series of C-shaped members that span the distance between support structures or support walls. These C-shaped members are commonly referred to as floor joists. The ends of the joists are coupled to tracks referred to as joist rims that are either supported on a wall or other structure by one of their flanges or have their webs attached to the wall or structure. The joists are commonly attached to the joist rims by conventional L-shaped clips or by tabs that are integrally formed in the web of the joist rim.
In those instances wherein the span is too long or loading conditions require it, beams known as girders are employed. The girders serve as points of attachments for the ends of adjacent floor joists as shown in FIG. 8. In the past, many floor girders 110 were fabricated utilizing a conventional stud 112 nested in a conventional track 118. The flanges of the track 118 and stud 112 were attached together utilizing screws 119 or welds. The floor joists 120 were then attached to the girder 110 by means of L-shaped clips 122 and screws. Such approach required extra labor to assembly the girders. In addition, when screws are used to assemble the girder, the screws cause the flooring material to be raised up or bulge in the area around each screw head.
Thus, as can be appreciated from the forgoing discussion, a variety of different components utilized in constructing residential and commercial buildings from steel are fabricated from conventional C-shaped studs and tracks. While the use of such components affords a host of advantages over the use of wood beams and the like, the added labor and materials required to fabricate such components undesirably lead to increased construction costs.